Biomass materials contain valuable materials that may be used in a variety of applications such as the production of fuels, feeds and chemicals. The release, segregation and collection of these useful materials are accomplished in the art using a variety of chemical, mechanical and enzymatic processes. Of primary benefit is the release of fermentable sugars such as hexose and pentose that can then be used in the production of ethanol. For these processes to be effective, it is desirable to modify the biomass mechanically and chemically.
Prior art references disclose methods for treating fibers with ammonia. U.S. Pat. No. 4,644,060 discloses a method for increasing the bioavailability of polysaccharide components of ligno-cellulosic materials by treatment with ammonia in a supercritical or near-supercritical fluid state at temperatures ranging from 100 degrees C. to 200 degrees C. and pressures ranging from 6.9 MPa to 35 MPa. U.S. Pat. Nos. 5,171,592 and 5,473,061 and US Pre-Grant Publication number 20080008783 describe methods for exploding biomass by rapidly reducing the pressure at which the biomass is treated, thereby exposing the value components in biomass to swelling agents such as ammonia and amines. These processes require high pressure vessels and are difficult and cumbersome to run cost effectively.